Rotary surface-finishing tool



July 22, 1952 R. o. PETERSON. 2,603,921 I ROTARY SURFACE-FINISHING TOOL Filed April 30, 1949 INVENTOR. I RUBEN 0. PETERSON Mm Mays.

construction. Any of the powdered abrasives such as Carborundum or Alundum, for example,"

' may be incorporated with the bondingmaterial which is ordinarily an elastomer. For ease of assembly of the operating element the bonding" material such as neoprene may be provided iin sheet form and alternate layers of such sheet and the wire cloth may be stacked one upon theother, compressed under pressure, and the neoprene then cured. Asin the case of the Fig. 3 construction, the finished element may likewise be cut to desired contour. It will of course be apparent that when the wire stem member is parallelto one set of strands composing thewire mesh there will be provided brushing strands operative'toact upon'both-the sides and end of a blind passage If desired, the several layers" of wire cloth' or screening may be superimposedand bonded togetherflwith the component Strands. of one layer lying "fat an angle .to strands .of' other layers, and this'may be desirable incertaininstances as where the finished element is to have a tapered contour, for example. I

Tools of the type above described may desirably be mounted iri holders (Fig. 7-9) 7 comprising a tubular portion l'2and a shank l3 adapted to be inserted in a drill press collet, for example. Bore M i of tubular portion I2 is dimensioned to receive thetwist'edstem 4 of my new tool with the brushing element l5held and supported in transverse-"slot IS in the end'of such tubularportion I2. The fbrushing element l5.corresponds to the element 1 of Fig. 1' or any ofthe various modifications. thereof. A set screw. 11 may be employed to secure stem 4' in place.v It will thus'be seen-that means is provided for supporting-the brushing element in a convenient manner per-' mitting ready replacement of the latter when necessary;:and without anydanger of either the wire retaining'member-E or of tubular holder 12 contacting'and damaging the work-piece.

- In Fig. there is illustrated another embodiment of my invention wherein a, strip of felt I8, similar to element I of Fig.1 but much more elongated,. is clamped between retaining wire portionsnlfi doubled "through hole 20, which latter wire portions are twisted after formation of twisted stem portion 4 to impart a helical configurationtosuch strip oi'feltasshown. The

' end-of thelatter is, of course, adapted to act upon the end ofa'blind hole or passageway and further serves to prevent contact of the doubled retaininggwire withthc work. v j

r 7 While thefelt oriother-operating element may ordinarily be lsufificiently firmly secured between the wiregportionsi simply by, twisting such portions together asexplained, it is often desirable to forciblypress such wireportions together,- as between dies, tocompact and secure such element therebetween. .Pressures on the order of 10,000 to 20,000 lbs. per square inch or more may sometimes be imposed although onsiderably lower pressures are sufficient where the operating element -is of relatively compressible --material. Where high pressures are employedpthe wirewill desirably havea: iiat face, as with-half-round 4 wire, which will be directed toward the element to obviate any danger of cutting the latter. A more rigid structure is likewise obtained and flexure is not concentrated along a single line in use.

When a tool of the Fig. 10 type is to be produced having arelatively long strip of material to be secured between retaining wire portions, it

is particularly desirable that such portions be fiat faced asabov'e' described and that thematerial be compacted therebetween by application of pressure. The stem portion 4 will then preferably betwistedprior to twisting of such retaining portions.

. The operating. or brushing element may comprise a wide variety of materials, as above indicated. "Such materials should, however, be selfsupportingfi. e..not limp) and will be selected for the particular use contemplated. Thus, layelement, while self-supporting, should not be em tirely rigid-but should be capable of flexing. in use. The woven-wire cloth-l 0 will therefore preferably be of wire; of the -type used "in power brushes having a certain resilience and snapaction. Layers of cotton fabric :buif material and -,similar .iabrics may be stapledor riveted togetherrather than bonded if a softer-buff-type element is desired and, in fact, insome cases the clamping action of the wire retaining member may be relied upon tosecure a plurality of such layers of sheet material without any means being provided actually attaching the layerstogether.

. The surface-finishing element will thus be seen to comprise a. generally flat sheet of substantial thickness (so as to present an eiiective workcontacting surface) of flexible; material, which for. many purposes will alsobe resilient in char.- acter. Such element should of course be. of a contour symmetrical relative, to thewire stem member which definesthe axisof rotation.

The wire stem member may be considered a passing; through the body of the surface-finishing' elementwhether it is, forced through, inserted through a hole, or doubled through a notch therein. In any event, the point of doubling of gether, as by soldering, clipping or wrapping, or

insertion irna suitable holder. Twisting is ordinarily a .suitable method; however, being quick andinexpensive, and even when pressures in excens of the tensile strength'of the wire are required to be imposed to compactv the body of the surfaceefinishing elementbetween the doubled portions of the wire, when such element has been thuscompacted'thewire will be found sufiiciently strong toretain'the material in compacted state. Instead of steel or other metal wire, it will be apparent that equivalentelongated stem members of suitable synthetic plastic materials may be employed.

While, in the Fig. 10 embodiment, an elongated rectangular sheet or strip 18 is shownwith the wire l9 passed therethroug'h at a point on the longitudinal axis adjacent one end thereof, it will be understood that such end may instead'be slitted or notched-to receive the doubled wire.

Also, the strip or sheet of surface-finishing material may, for example, be of greater width adjacent the twisted stem 4 and taper toward the end, depending on the particular operation for which the tool is designed.

The term surface-finishing as employed herein is intended to include cleaning, polishing and like operations.

Other modes of applying the principle of the invention may be employed, change being made as regards the details'described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A rotary toolcomprising in combination a working element and a holder therefor; said element comprising a sheet of substantial thickness of self-supporting flexible material and a wire stem member passing through said sheet and doubled upon itself to clamp such material between straight parallel portions of said member, such portions extending beyond said sheet to form a stem; and said holder comprising a tubular member adapted to receive such stem therein, with the end of said tubular member being slotted to receive said sheet and thereby support the side and end portions of the same, the depth of such slot being less than the axial extent of said sheet so that a portion of said sheet will protrude axially beyond the end of said tubular member when seated therein; and means securing said stem within said holder.

2. A rotary surface-finishing tool adapted to be rotated at high speeds about its axis simultaneously to act upon both laterally and axially disposed work surfaces, as within a blind hole in a work-piece, comprising a generally flat symmetrical body of flexible self-supporting abrasive material, an elongated stem member formed into a loop passed through such material at a point spaced inwardly from the edges thereof and doubled upon itself to clamp the flat sides of such material between parallel portions, said member extending beyond said body to form a stem; a

holder comprising a tubular member adapted to receive such stem therein, with the end portion of said tubular member being slotted longitudinally thereof to receive said fiat symmetrical body of abrasive material and support the same, the axial extent of such slot being less than the axial extent of said body of abrasive material so that a portion of said body will protrude laterally of said tubular member and also axially beyond the end thereof when said body is seated in said slot; and means adapted to secure such stem within said tubular holder.

3. A rotary tool adapted to be rotated about its axis to act simultaneously upon both laterally and axially disposed work surfaces, as within a blind'hole in a work-piece, comprising a, generally fiat symmetrical body of sheet material, an elongated holder member having a longitudinally slotted end with said body of sheet material symmetrically received in such slot and projecting therefrom both laterally and to a lesser longitudinal extent axially of said holder member, and means adapted to secure said sheet material thus positioned in such slot.

RUBEN 0. PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,361,861 Howell Dec. 14, 1920 1,389,071 Pessels Aug. 30, 1921 

